H.J. Heinz Co. and its directors were sued by investors who contend they will be shortchanged in the ketchup maker’s proposed $23 billion acquisition by Berkshire Hathaway Inc. and 3G Capital Inc.

Heinz, based in Pittsburgh, said Feb. 14 that Berkshire and 3G will pay $72.50 a share, a 20 percent premium at the time and the largest-ever food industry transaction.

The buyout stems from “an unfair process” and allows the board and management to cash in more than 5.6 million shares of otherwise “illiquid holdings” for more than $400 million, James Clem, a Heinz shareholder, said in one of two complaints filed Feb. 15 in federal court in Pittsburgh.

Investors’ lawyers ask for a jury trial and an order to stop the buyout under its present terms.

Michael Mullen, a spokesman for Heinz, declined to comment on the complaints.

After the deal was announced, the U.S. Federal Bureau of Investigation said it is working with the Securities and Exchange Commission in a criminal probe of trading “anomalies” before the news became public.

‘Iconic Brands’

Plaintiffs’ lawyers said in court papers that Heinz is “the most global of all U.S.-based food companies, famous for its iconic brands” in 200 countries on six continents. Heinz, “synonymous with ketchup,” sells 650 million bottles of the condiment annually, along with about “two single-serve packets of ketchup for every man, woman and child on the planet.”